The flowers attract long-tongued and short-tongued bees, including bumblebees and Halictid bees. Beetles and Syrphid flies may also visit the flowers, but they are less effective pollinators. The reward of these insects is the abundant pollen, as the flowers produce no nectar. The caterpillars of the butterfly Strymon melinus (Gray Hairstreak) reportedly eat the seed capsules, while the caterpillars of the moth Nedra ramosula (Gray Half-Spot) feed on the foliage. Mammalian herbivores usually don't consume this plant because the leaves contain hypericin – a photosensitive toxin. Light-skinned animals are especially sensitive to this toxin, which can cause the skin to blister in sunlight. It can also cause gastrointestinal irritation.